Prominent Bahraini human rights activist Nabeel Rajab has been sentenced to three months in jail on charges linked to anti-government messages he posted on Twitter.

Monday verdict against the activist relates to a tweet he wrote in June, saying that residents of the town of Muharraq had made a recent show of support for the country's prime minister only because they were paid to do so. Rajab, who heads the Bahrain Center for Human Rights, has been a fierce critic of the state’s crackdown on protesters during months of unrest.

Prosecutors alleged that the post slandered the residents of the island town, which is home both to Sunni and Shiite Muslims.

"Every day there are a thousand people insulting a thousand people, this isn't logical. Normally the charge of insult leads to just a fine. So for me [the court’s ruling] is a surprise," said the activist’s lawyer as quoted by Reuters.

As the verdict was announced, police took Rajab from his home in the Bani Jamra district west of the capital Manama, says the activist’s wife Sumaya.

Rajab's attorneys will prepare an appeal. If the appeal fails, the lawyers hope the activist’s time in jail will be shortened, as the man has already served three weeks in connection with the case.

Monday's conviction resolves just one of several cases against Rajab, who has been arrested and released twice since early May.

The last time Rajab was detained was right after recording The Julian Assange Show, set up by the WikiLeaks founder and premiered on RT. In the show, Rajab slammed the US and Saudi Arabia for supporting the Bahraini monarchy while calling on Syria’s President Bashar Al-Assad to step down.

On June 27, Rajab was released. Around this time, the activist was fined 300 dinars (about $800) over a critical Twitter message addressing the Interior Ministry.

The court’s ruling may not go down well with Rajab’s thousands of supporters, who staged massive protests in June following the activist’s arrest. The small kingdom in the Persian Gulf has seen 16 months of anti-regime demos, in which Rajab has been a key figure.

The Gulf Arab state, which houses the US Navy's Fifth Fleet, is ruled by the Sunni al-Khalifa family, while the Shiite population has been calling for democratic reforms. One of the major demands is the ouster of the prime minister, who has been in office since 1971. Many Sunnis, who fear empowering Shiite Islamists in the opposition, see him as a key support figure.

Stun grenades, tear gas and pepper spray have been used on pro-democracy protesters in the months of their civil action. Official reports say around 85 civilians were killed in clashes with police, but activists insist the real number is many times greater.